Economy and Ethnicity in Transylvania

This chapter discusses the most important social domain that is not organized along ethnic lines in Transylvania, namely the economy. The chapter aims to answer two general questions: First, to what extent is Romania’s democracy and economic institutional system able to capitalize on the potential assets stemming from ethnic diversity? Second, what kind of cultural, structural, and network resources do Transylvanian Hungarians possess, to what extent and how do they succeed in utilizing them in the economy? The main conclusion of the chapter is that the economic sector is not perceived as being ethnically divided in Transylvania; there are, however, a number of initiatives that may point toward an ethnically coordinated economic sector

Infection-related variation in cuticle thickness in the ant Myrmica scabrinodis (Hymenoptera: Formicidae)

Cuticle quality is of vital importance in insects. It prevents desiccation, provides mechanical strength and protects against pathogens. The within-species variation of cuticular structure is affected by many factors. We investigated the relationship of the presence/absence of the ectoparasitic fungus Rickia wasmannii and cuticle thickness of its ant host Myrmica scabrinodis. Infected ants had thinner cuticle than uninfected ones, while there were also differences among populations. It is unclear whether reduced thickness is the host's response, or whether the fungus infects preferentially colonies with ants that have a thin cuticle. Either way, within-species variation is linked to the presence of an epicuticular parasite

Infection-related variation in cuticle thickness in the ant Myrmica scabrinodis (Hymenoptera: Formicidae)

© 2018, International Union for the Study of Social Insects (IUSSI). Cuticle quality is of vital importance in insects. It prevents desiccation, provides mechanical strength and protects against pathogens. The within-species variation of cuticular structure is affected by many factors. We investigated the relationship of the presence/absence of the ectoparasitic fungus Rickia wasmannii and cuticle thickness of its ant host Myrmica scabrinodis. Infected ants had thinner cuticle than uninfected ones, while there were also differences among populations. It is unclear whether reduced thickness is the host’s response, or whether the fungus infects preferentially colonies with ants that have a thin cuticle. Either way, within-species variation is linked to the presence of an epicuticular parasite.status: publishe

Under pressure: the effect of long-term fungal infection on the encapsulation response in ants

Long-term exposure to infections can exert serious pressure on the host's immune system and influence its capacity to react adequately when challenged by another parasite. Rather than reacting readily to the attack of a secondary pathogen the immune response might be weaker because of the costs imposed by resisting the primary infection. Rickia wasmannii is an ectoparasitic fungus, which attaches to the outer layer of Myrmica ants without killing the host, but causing different modifications on individual and social level. We examined the immune competence of M. scabrinodis workers of different age categories either coming from infected colonies or from healthy control colonies using encapsulation assays. Infection and age did not affect the encapsulation response separately, but their interaction had a considerable effect: the response was stronger in young, infected workers. Smaller individuals also had stronger responses. Encapsulation response was not influenced by fat content of workers. Immune facilitation might indeed work in infected colonies, although not for each worker category. This emphasizes the importance of within-colony diversity when considering colony level response to parasitic attacks

Geographical variation in ant foraging activity and resource use is driven by climate and net primary productivity

Aim Foraging activity is critical for animal survival. Comprehending how ecological drivers influence foraging behaviour would benefit our understanding of the link between animals and ecological processes. Here, we evaluated the influence of ecological drivers on ant foraging activity and relative resource use. Location Six Brazilian biomes: Amazon, Atlantic rainforest, Caatinga, Cerrado, Pampa and Pantanal. Taxon Formicidae. Methods We assessed ant foraging activity and resource use by sampling across 60 sites. We placed baited tubes that contained one of five liquid resources (sugar, lipids, amino acid, sodium and distilled water). We used model selection to assess the influence of ecological drivers (temperature, precipitation, temperature seasonality and net primary productivity) on ant foraging activity and relative resource use. Results Foraging activity was higher in wetter, more productive and less thermally seasonal environments. The relative use of amino acids increased at higher temperatures while the relative use of lipids decreased. The relative use of sugar increased in drier and less productive environments with high-temperature seasonality while the relative use of amino acid and sodium decreased in those environments. The relative use of lipids was complex: increasing with increasing temperature seasonality and decreasing with increasing precipitation. Furthermore, the relative use of sodium was greater where the foraging activity was high. Main conclusions We demonstrate how ecological drivers are correlated with ant foraging activity and resource use in the field across large spatial scales. The search for resources encompasses different interactions involving ants with abiotic and biotic components in the ecosystem. Thus, we suggest that changes in climate and NPP, which influence the intensity and the way that ants search for resources, will result in changes in ant-mediated ecological processes